Sen. Josh Hawley of Missouri has concerns about Neomi Rao, the woman nominated to fill Supreme Court Justice Brett Kavanaugh’s seat on the influential D.C. Circuit Court of Appeals. Hawley wrote a letter to Rao on Tuesday outlining concerns with her judicial philosophy, especially when it comes to abortion issues.

“She does not have a strong record on life. She has written some things in the past that suggests to me she may be more of a judicial activist,” Hawley said in a radio interview on Monday.

After reviewing Rao’s academic writings, Hawley said he is especially concerned about her views on substantive due process. Conservatives often oppose using the doctrine of substantive due process to provide for some rights, including the right to privacy and abortion. These rights not stated in the constitutional text, but according to some court rulings are purportedly implied by it. Hawley tweeted, “The implied fundamental rights cases are where the courts just make stuff up. I’m opposed to that. And I will ask every judicial nominee whether she or he is too.”

Cases like Roe v. Wade and Casey v. Planned Parenthood, which established a constitutional right to abortion, are also two substantive due process precedents that Hawley fears Rao would overturn if nominated. “I have concerns about your views on whether the Constitution confers substantive constitutional rights to dignity and whether those rights trump democratically passed laws,” Hawley wrote in his letter.

It would only take a few Republicans voting “no” to reject Rao’s confirmation in the Senate, where Republicans hold a slim 53-47 majority. Other conservatives, including Judicial Crisis Network and the Wall Street Journal editorial board, have attacked Hawley for his opposition to Rao.

Hawley and Rao are scheduled to meet on Wednesday, prior to the Senate Judiciary Committee’s vote on her nomination.

Madeline is a staff writer at the Federalist and the producer of The Federalist Radio Hour. Follow her on Twitter.